Growth, thermal and spectral properties of Tm3+, Ho3+ co-doped NaGd(MoO4)2 Crystal

A Tm3+/Ho3+:NaGd(MoO4)2 crystal was grown by the Czochralski method. The XRD results matched standard data from JCPDS file, which accorded with scheelite structure with an I41/a space group. Thermal properties of crystal were analyzed by using the TG-DSC curve. The melting point and specific heat are 1182 °C and 0.5 J/g K at 300 K, respectively. The Spectral properties of the Tm3+/Ho3+:NaGd(MoO4)2 crystal were investigated, including room temperature absorption spectrum and fluorescence spectrum. The absorption cross-section of Tm3+ at 796 nm is 4.33 × 10−20 cm2 with pertinent full widths at half maximum (FWHM) of 10 nm. The intensity parameters, spontaneous emission probability, fluorescence branching ratios and radiative lifetimes were calculated by Judd-Ofelt theory. The emission cross-sections are 1.47 × 10−20 cm2 and 1.36 × 10−20 cm2 for Tm3+ at 1850 nm and Ho3+ at 2000 nm respectively. The lifetime of 5I7 → 5I8 (Ho3+) was 4.263 ms.